Pink Blanket Of Flamingos, Rift Valley Lakes, Nakuru Lake National Park, Kenya

Genetic studies since 2004 have identified a major clade of birds, which has been named the Metaves. This group includes flamingos and grebes, as well as the hoatzin, pigeons, hummingbirds, and the sunbittern. Most of these groups have been difficult to place on the family tree of birds. Relations within this group are somewhat unclear, and it has been suggested that this clade is based on molecular convergence.
Morphological evidence also strongly supports a relationship between flamingos and grebes. They hold at least eleven morphological traits in common, which are not found on other birds. Many of these characteristics have been previously identified on flamingos, but not on grebes. The fossil Palaelodids can be considered evolutionarily, and ecologically, intermediate between flamingos and grebes.
For the grebe-flamingo clade, the taxon Mirandornithes ("miraculous birds" due to their extreme divergence and apomorphies) has been proposed. Alternatively, they could be placed in one order, with Phoenocopteriformes taking priority.